支链数目和支链长度对梳形支化聚苯乙烯动态粘弹行为的影响  

Effects of Degree of Branching and Branch Length on the Dynamic Viscoelastic Behavior of Comb-Like Branched Polystyrene

作　　者：蒋姗[1] 徐晓梅[1] 王美玉[1] 朱梦冰[1] 王克敏[1] 俞强[1] 

机构地区：[1]常州大学材料科学与工程学院江苏省太阳能电池材料与技术重点实验室,江苏常州213164

出　　处：《高分子材料科学与工程》2016年第1期63-67,共5页Polymer Materials Science & Engineering

基　　金：江苏高校优势学科建设工程资助项目;国家自然科学基金资助项目(21304011)

摘　　要：以主链长度相当、支链数目和支链长度依次变化的梳形支化聚苯乙烯为对象,使用平板式旋转流变仪测定其动态粘弹参数的温度谱和频率谱,研究了支链数目和支链长度对梳形支化聚苯乙烯动态粘弹行为的影响。结果表明,梳形支化聚苯乙烯的玻璃化转变温度高于相同相对分子质量范围的线型聚苯乙烯,而且随支链数目增加其玻璃化转变温度持续增大;梳形支化聚苯乙烯的粘流转变温度低于相同相对分子质量范围的线型聚苯乙烯,随支链长度增加,粘流转变温度和橡胶弹性平台区储能模量明显增大。与主链运动相对应的松弛过程发生在低频区,其特征松弛时间随支链数目增加明显延长,在更高频率下会出现与梳形支化聚苯乙烯的支链解缠结相关的支链松弛,随支链长度增加,支链特征松弛时间延长。A series of comb-like branched polystyrene（ C-PS） samples with equal backbone lengths,different degrees of branching and branch lengths were synthesized. The temperature and frequency spectra of their dynamic viscoelastic parameters were determined by a rotational rheometer,and the effect of branching structure on the dynamic viscoelacstic behavior of C-PS was investigated. The results show that,the glass transition temperature（ Tg） of C-PS is higher than that of linear PS（ L-PS） with the same molecular weight,and Tgincreases as the degree of branching is improved. However,the viscous flow temperature（ Tf） of C-PS is lower than that of L-PS with the same molecular weight.With the branch length turning longer,the Tfand storage modulus（ G＇） in rubbery region both increase significantly.Relaxation corresponding to backbone motion of C-PS occurs in low frequency area. The characteristic relaxation time becomes longer with degree of branching increasing. In higher frequency area,the relaxation corresponding to branch motion occurs. The characteristic relaxation time also turns longer with branch length increasing.

关 键 词：梳形支化聚苯乙烯 动态粘弹行为 支链松弛 支链数目 支链长度 

分 类 号：TQ325.2[化学工程—合成树脂塑料工业]